38. Hydatidiform mole

Overview. At the marked rectangle you can easily compare normal and abnormal villi side by side.

Staining: HE

Organ: Placenta?

Description:

Both abnormal and normal chorionic villi are present, indicating that this is a partial hydatidiform mole.

The abnormal villi show hydropic swelling, making them much larger than normal villi. They also have a loose, myxomatous and oedematous stroma.

Alternatively, it's a complete mole because of lack of foetal elements and the relatively severe atypia.

Diagnosis: Partial or complete hydatidiform mole (my teacher said partial, others apparently say complete)

Risk factor:

• Asian countries
• Women < 20 or > 40

Theory:

Partial hydatidiform moles usually contain some foetal cells but we do not have to recognize those.

Abnormal chorionic villus

Normal vs abnormal villus